BS 5535:1978

Foreword
Cooperating organizations
Specification
1. Scope
2. References
3. Nomenclature and definitions
4. Material
5. Finish
6. General features of design
7. Recommended sizes
8. Accuracy
9. Matched pairs of box angle plates
10. Protection against climatic conditions
11. Marking
Appendix
A. Recommended chemical compositions of plain and
    alloy cast irons, and method of heat treatment
Tables
1. General dimensions of right angle plates and box
    angle plates
2. Tolerances for right angle plates and box angle
    plates
Figures
1. Right angle plate: unwebbed
2. Right angle plate: webbed
3. Box angle plate
4. Exaggerated illustration of squareness tolerance
5. Granite right angle plate
6. Granite box angle plate

Provides for three grades of plates made from steel, cast iron or granite in the size range 60 x 50 mm to 600 x 500 mm. Nomenclature, material finish, design, sizes, accuracy, matched pairs, protection and marking. Appendix recommends types of plain and alloy cast iron and method of heat treatment.

This British Standard relates to angle plates ranging in size from 60 mm × 50 mm to 600 mm × 500 mm. Successive sizes are in a series in which the dimensions increase by about the same ratio throughout.

Three grades, viz AA, A, and B, are provided according to three magnitudes of tolerance for squareness and the associated properties of flatness and parallelism of surfaces.